The present invention relates to an optical fiber amplifier surge protective apparatus for complementing a hit of an optical signal by monitoring the level of a branch optical signal branched from the optical signal.
In a wave length division multiplexing (WDM) optical transmission system using an optical fiber amplifier, when a hit occurs on an optical fiber line, and the line recovers from the continuous hit, an optical signal is abruptly input to the optical fiber amplifier in a no-signal state to generate an optical surge. Such optical surge is a phenomenon in which energy stored by pumping light during a no-signal state is induced and emitted at once by a newly input optical signal after the recovery of the optical fiber line. This optical surge damages optical components such as a light-receiving element.